2023 JEEP WRANGLER warning light

STARTING AND OPERATING129
(Continued)
AFTER STARTING
The idle speed is controlled automatically and will
decrease as the engine warms up.
STARTING THE ENGINE — DIESEL ENGINE
(IF EQUIPPED)
Before starting your vehicle, adjust your seat, both inside
and outside mirrors, and fasten your seat belts.
The starter is allowed to crank for up to 25-second
intervals. Waiting two minutes between such intervals will
protect the starter from overheating.
NOTE:Engine start up in very low ambient temperature could
result in evident white smoke. This condition will
disappear as the engine warms up.
AUTOMATIC TRANSMISSION
Start the engine with the transmission gear selector in the
PARK (P) position. Apply the brake before shifting to any
driving range.
EXTREME COLD WEATHER
The cartridge block heater clips into the engine block near
the water jacket and transfers heat to the coolant. It
requires a 110–115 Volt AC electrical outlet with a
grounded, three-wire extension cord. Its use is
recommended for environments that routinely fall below
-10°F (-23°C). It should be used when the vehicle has not
been running overnight or longer periods and should be
plugged in for two hours prior to start. Its use is required
for cold starts with temperatures under -20°F (-28°C).
NOTE:The engine block heater and heater cord are
factory-installed options. If your vehicle is not equipped,
heater and heater cords are available from an authorized
Mopar® dealer.
A 12 Volt heater built into the fuel filter housing aids in
preventing fuel gelling. It is controlled by a built-in ther -
mostat.
 A Diesel Pre-Heat system both improves engine
starting and reduces the amount of white smoke
generated by a warming engine.
WARNING!
Before exiting a vehicle, always come to a complete
stop, then shift the automatic transmission into
PARK and apply the parking brake.
 Always make sure the ignition is in the OFF position,
key fob is removed from the vehicle and vehicle is
locked.
 Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Leaving children in a
vehicle unattended is dangerous for a number of
reasons. A child or others could be seriously or fatally
injured. Children should be warned not to touch the
parking brake, brake pedal or the gear selector.
Do not leave the key fob in or near the vehicle, or in
a location accessible to children, and do not leave
the ignition of a vehicle equipped with Keyless
Enter ‘n Go™ in the ACC or ON/RUN position. A child
could operate power windows, other controls, or
move the vehicle.
 Do not leave children or animals inside parked vehi -
cles in hot weather. Interior heat buildup may cause
serious injury or death.
CAUTION!
 The engine is allowed to crank as long as
25 seconds. If the engine fails to start during this
period, please wait at least two minutes for the
starter to cool before repeating start procedure.
 If the Water in Fuel Indicator Light remains on, DO
NOT START engine before you drain the water from
the fuel filters to avoid engine damage
Úpage 321.
WARNING!
4

23_JL_OM_EN_USC_t.book Page 129

130STARTING AND OPERATING
NORMAL STARTING
Observe the instrument cluster lights when starting the
engine.
NOTE:Normal starting of either a cold or a warm engine is
obtained without pumping or pressing the accelerator
pedal.

1. Always apply the parking brake.

2. Press and hold the brake pedal while pushing the
ENGINE START/STOP button once.
NOTE:A delay of the start of up to five seconds is possible under
very cold conditions. The Wait to Start telltale will be illumi -
nated during the preheat process. When the engine Wait
To Start telltale goes off the engine will automatically
crank.
3. The system will automatically engage the starter to crank the engine. If the vehicle fails to start, the
starter will disengage automatically after 25 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push the ENGINE START/STOP
button again. 5. Check that the Oil Pressure Warning Light has turned
off.
6. Release the parking brake.
STARTING FLUIDS
The engine is equipped with a glow plug preheating
system. If the instructions in this manual are followed, the
engine should start in all conditions and no type of starting
fluid should be used.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is operating:
 All message center lights are off.
 Malfunction Indicator Light (MIL) is off.
 Engine Oil Pressure telltale is not illuminated.
 Voltmeter operation.
The voltmeter may show a gauge fluctuation at various
engine temperatures. This is caused by the glow plug
heating system. The number of cycles and the length of
the cycling operation is controlled by the engine control
module. Glow plug heater operation can run for several
minutes. Once the heater operation is complete, the
voltmeter needle will stabilize.
CAUTION!
If the Water in Fuel Indicator Light remains on, DO NOT
START the engine before you drain the water from the
fuel filters to avoid engine damage
Úpage 321.
WARNING!
 Do not leave children or animals inside parked vehi -
cles in hot weather. Interior heat buildup may cause
serious injury or death.
 When leaving the vehicle, always make sure the
keyless ignition node is in the OFF position, remove
the key fob from the vehicle and lock the vehicle.
 Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing children to
be in a vehicle unattended is dangerous for a
number of reasons. A child or others could be seri -
ously or fatally injured. Children should be warned
not to touch the parking brake, brake pedal or the
gear selector.
 Do not leave the key fob in or near the vehicle, or in
a location accessible to children, and do not leave
the ignition of a vehicle equipped with Keyless
Enter ‘n Go™ in the ACC or ON/RUN position. A child
could operate power windows, other controls, or
move the vehicle.

23_JL_OM_EN_USC_t.book Page 130

132STARTING AND OPERATING
STOPPING THE ENGINE
After full load operation, idle the engine for a few minutes before shutting it down. This idle period will allow the lubricating oil and coolant to carry excess heat away from the
turbocharger.
NOTE:Refer to the following chart for proper engine shutdown.
NOTE:Under certain conditions the engine fan will run after the
engine is turned off. These conditions are under high load
and high temperature conditions.
COOLING SYSTEM TIPS — AUTOMATIC
T
RANSMISSION
To reduce the potential for engine and transmission
overheating in high ambient temperature conditions, take
the following actions:
 City Driving — When stopped, shift the transmission
into NEUTRAL (N) and increase engine idle speed.
 Highway Driving — Reduce your speed. 
Up Steep Hills — Select a lower transmission gear.
 Air Conditioning — Turn it off temporarily.
NOTE:If the coolant temperature is too high, the A/C will auto -
matically turn off.
Do Not Operate The Engine With Low Oil
Pressure
If the Oil Pressure Warning Light turns on while driving,
stop the vehicle and shut down the engine as soon as
possible. A chime will sound when the light turns on. After
the vehicle is safely stopped, restart the engine and
monitor the Oil Pressure Warning Light. If the Oil Pressure
Warning Light is still illuminated, turn the engine OFF and contact an authorized dealer for further assistance. If the
lamp is no longer illuminated, the engine can be operated
but it is recommended to take the vehicle to an authorized
dealer as soon as possible.
NOTE:Do not operate the vehicle until the cause is corrected.
This light does not show how much oil is in the engine. The
engine oil level must be checked under the hood.
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine Shutdown
Stop and Go EmptyCoolNone
Stop and Go Medium 0.5
Highway Speeds MediumWarm 1.0
City Traffic Maximum GCWR 1.5
Highway Speeds Maximum GCWR 2.0
Uphill Grade Maximum GCWR Hot2.5
CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could result
in immediate and severe engine damage.

23_JL_OM_EN_USC_t.book Page 132

STARTING AND OPERATING133
Do Not Operate The Engine With Failed
Parts
All engine failures give some warning before the parts fail.
Be on the alert for changes in performance, sounds, and
visual evidence that the engine requires service. Some
important clues are:
Engine misfiring or vibrating severely
 Sudden loss of power
 Unusual engine noises
 Fuel, oil or coolant leaks
 Sudden change, outside the normal operating range, in
the engine operating temperature
 Excessive smoke
 Oil pressure drop
ENGINE BREAK-IN RECOMMENDATIONS —
GASOLINE ENGINE (IF EQUIPPED)
A long break-in period is not required for the engine and
drivetrain (transmission and axle) in your vehicle.
Drive moderately during the first 300 miles (500 km).
After the initial 60 miles (100 km), speeds up to 50 or
55 mph (80 or 90 km/h) are desirable.
While cruising, brief full-throttle acceleration within the
limits of local traffic laws contributes to a good break-in.
Wide-open throttle acceleration in low gear can be
detrimental and should be avoided.
The engine oil installed in the engine at the factory is a
high-quality energy conserving type lubricant. Oil changes
should be consistent with anticipated climate conditions
under which vehicle operations will occur. For the recommended viscosity and quality grades
Úpage 374.
NOTE:A new engine may consume some oil during its first few
thousand miles (kilometers) of operation. This should be
considered a normal part of the break-in and not inter
-
preted as a problem.
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE (IF EQUIPPED)
The diesel engine does not require a break-in period due
to its construction. Normal operation is allowed, providing
the following recommendations are followed:
 Warm up the engine before placing it under load.
 Do not operate the engine at idle for prolonged periods.
 Use the appropriate transmission gear to prevent
engine lugging.
 Observe vehicle oil pressure and temperature indica -
tors.
 Check the coolant and oil levels frequently.
 Vary throttle position at highway speeds when carrying
or towing significant weight.
NOTE:Light duty operation such as light trailer towing or no load
operation will extend the time before the engine is at full
efficiency. Reduced fuel economy and power may be seen
at this time.
The engine oil installed in the engine at the factory is a
high-quality energy conserving type lubricant. Oil changes
should be consistent with anticipated climate conditions
under which vehicle operations will occur. For
recommended viscosity and quality grades see
Úpage 374. NON-DETERGENT OR STRAIGHT MINERAL
OILS MUST NEVER BE USED.
PARKING BRAKE
Before exiting the vehicle, make sure that the parking
brake is fully applied. Also, be certain to leave an
automatic transmission in PARK, or manual transmission
in REVERSE or FIRST gear.
The parking brake lever is located in the center console.
To apply the parking brake, pull the lever up as firmly as
possible. To release the parking brake, pull the lever up
slightly, push the center button, then lower the lever
completely.
CAUTION!
Never use Non-Detergent Oil or Straight Mineral Oil in
the engine or damage may result.
4

23_JL_OM_EN_USC_t.book Page 133

134STARTING AND OPERATING
(Continued)

Parking Brake Lever

When the parking brake is applied with the ignition switch
ON, the Brake Warning Light in the instrument cluster will
illuminate.
NOTE:
When the parking brake is applied and the automatic
transmission is placed in gear, the Brake Warning Light
will flash. If vehicle speed is detected, a chime will
sound to alert the driver. Fully release the parking
brake before attempting to move the vehicle.
 This light only shows that the parking brake is applied.
It does not show the degree of brake application.
When parking on a hill, it is important to turn the front
wheels toward the curb on a downhill grade and away from
the curb on an uphill grade. For vehicles equipped with an
automatic transmission, apply the parking brake before
placing the gear selector in PARK, otherwise the load on
the transmission locking mechanism may make it difficult
to move the gear selector out of PARK.
MANUAL TRANSMISSION — IF EQUIPPED
WARNING!
 Never use the PARK position on an automatic trans -
mission as a substitute for the parking brake. Always
apply the parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
 When exiting the vehicle, always remove the key fob
from the ignition and lock your vehicle.
 Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing children to
be in a vehicle unattended is dangerous for a
number of reasons. A child or others could be seri -
ously or fatally injured. Children should be warned
not to touch the parking brake, brake pedal or the
gear selector.
 Do not leave the key fob in or near the vehicle, or in
a location accessible to children. A child could
operate power windows, other controls, or move the
vehicle.
 Be sure the parking brake is fully disengaged before
driving; failure to do so can lead to brake failure and
a collision.
 Always fully apply the parking brake when leaving
your vehicle or it may roll and cause damage or
injury. Also, be certain to leave an automatic trans -
mission in PARK, a manual transmission in REVERSE
or FIRST gear. Failure to do so may cause the vehicle
to roll and cause damage or injury.
CAUTION!
If the Brake Warning Light remains on with the parking
brake released, a brake system malfunction is
indicated. Have the brake system serviced by an
authorized dealer immediately.
WARNING!
You or others could be injured if you leave the vehicle
unattended without having the parking brake fully
applied. The parking brake should always be applied
when the driver is not in the vehicle, especially on an
incline.
CAUTION!
 Never drive with your foot resting on or partially
depressing the clutch pedal. Never attempt to hold
the vehicle on a hill with the clutch pedal partially
engaged. Operating vehicle in this manner may
cause the clutch to overheat and cause permanent
damage to the clutch. If you continue to operate the
vehicle in this manner, the “CLUTCH HOT” message
or Transmission Temperature Warning Light will be
displayed in the instrument cluster. For more infor -
mation
Úpage 116.

23_JL_OM_EN_USC_t.book Page 134

STARTING AND OPERATING139
The following indicators should be used to ensure that you
have properly engaged the transmission into the PARK
position:
When shifting into PARK, push the lock button on the
gear selector and firmly move the gear selector all the
way forward until it stops and is fully seated.
 Look at the transmission gear position display and
verify that it indicates the PARK position (P), and is not
blinking.
 With the brake pedal released, verify that the gear
selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward. Shift into
REVERSE only after the vehicle has come to a complete
stop.
NEUTRAL (N)
Use this range when the vehicle is standing for prolonged
periods with the engine running. Apply the parking brake
and shift the transmission into PARK if you must exit the
vehicle. DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
and the best fuel economy. The transmission
automatically upshifts through all forward gears. The
DRIVE position should be used for all normal operating
conditions.
When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading
conditions, in hilly terrain, traveling into strong head
winds, or while towing a heavy trailer), use the AutoStick
shift control to select a lower gear
Úpage 140. Under these conditions, using a lower gear will improve
performance and extend transmission life by reducing
excessive shifting and heat buildup.
During extremely cold temperatures (-22°F [-30°C] or
below), transmission operation may be modified
depending on engine and transmission temperature as
well as vehicle speed. Normal operation will resume once
the transmission temperature has risen to a suitable level.
MANUAL (M)
The MANUAL (M, +/-) position (beside the DRIVE position)
enables full manual control of transmission shifting also
known as AutoStick mode. Toggling the gear selector
forward (-) or rearward (+) while in the MANUAL (AutoStick)
position will manually select the transmission gear, and
will display the current gear in the instrument cluster
Úpage 140.
Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
mode is activated. In this mode, the transmission may
operate only in certain gears, or may not shift at all.
Vehicle performance may be severely degraded and the
engine may stall. In some situations, the transmission may
not re-engage if the engine is turned off and restarted. The
Malfunction Indicator Light (MIL) may be illuminated. A
message in the instrument cluster will inform the driver of
the more serious conditions, and indicate what actions
may be necessary.
CAUTION!

Before moving the transmission gear selector out of
PARK, you must start the engine, and also press the
brake pedal. Otherwise, damage to the gear selector
could result.
 DO NOT race the engine when shifting from PARK or
NEUTRAL into another gear range, as this can
damage the drivetrain.
WARNING!
Do not coast in NEUTRAL and never turn off the ignition
to coast down a hill. These are unsafe practices that
limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage.
 For Recreational Towing
Úpage 176.
 For Towing A Disabled Vehicle
Úpage 303.
4

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STARTING AND OPERATING141
FOUR-POSITION TRANSFER CASE —
I
F EQUIPPED

Four-Wheel Drive Gear Selector

The transfer case provides four positions:
 2H — Two-Wheel Drive High Range
 4H — Four-Wheel Drive High Range
 N (Neutral)
 4L — Four-Wheel Drive Low Range
For additional information on the appropriate use of each
transfer case position, see the following:
2H
Two-Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4H
Four-Wheel Drive High Range — This range maximizes
torque to the front driveshaft, forcing the front and rear
wheels to rotate at the same speed. This range provides
additional traction for loose, slippery road surfaces only. N (Neutral)
N (Neutral) — This range disengages both the front and
rear driveshafts from the powertrain. To be used for flat
towing behind another vehicle Úpage 176.
4L
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque to the front
driveshaft, forcing the front and rear wheels to rotate at
the same speed. This range provides additional traction
and maximum pulling power for loose, slippery road
surfaces only. Do not exceed 25 mph (40 km/h).
The transfer case is intended to be driven in the 2H
position for normal street and highway conditions, such as
hard-surfaced roads.
In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front and
rear wheels to rotate at the same speed. The 4H and 4L
positions are intended for loose, slippery road surfaces
only and not intended for normal driving. Driving in the 4H and 4L positions on hard-surfaced roads will cause
increased tire wear and damage to the driveline
components. For further information on shifting into 4H or
4L
Úpage 141.
The instrument cluster alerts the driver that the vehicle is
in four-wheel drive, and the front and rear driveshafts are
locked together. The light will illuminate when the transfer
case is shifted into the 4H position.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type, and circumference on each wheel.
Any difference will adversely affect shifting and cause
damage to the transfer case.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
Shifting Procedures
2H TO 4H OR 4H TO 2H
Shifting between 2H and 4H can be made with the vehicle
stopped or in motion. The preferred shifting speed would
be 0 to 45 mph (72 km/h). With the vehicle in motion, the transfer case will engage/disengage faster if you
momentarily release the accelerator pedal after
completing the shift. Do not accelerate while shifting the
transfer case. Apply a constant force when shifting the
transfer case lever.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the (N)
Neutral position without first fully engaging the parking
brake. The transfer case (N) Neutral position
disengages both the front and rear driveshafts from the
powertrain, and will allow the vehicle to roll, even if the
automatic transmission is in PARK (or manual
transmission is in gear). The parking brake should
always be applied when the driver is not in the vehicle.
4

23_JL_OM_EN_USC_t.book Page 141

STARTING AND OPERATING143
N (Neutral)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
behind another vehicle
Úpage 176.
4L
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque to the front
driveshaft, forcing the front and rear wheels to rotate at
the same speed. This range provides additional traction
and maximum pulling power for loose, slippery road
surfaces only. Do not exceed 25 mph (40 km/h).
This transfer case is designed to be driven in the
two-wheel drive position (2H) or four-wheel drive position
(4H AUTO) for normal street and highway conditions on dry
hard surfaced roads.
For variable driving conditions, the 4H AUTO mode can be
used. In this mode, the front axle is engaged, but the
vehicle's power is sent to the rear wheels. Four-wheel drive
will be automatically engaged when the vehicle senses a loss of traction. Because the front axle is engaged, this
mode will result in lower fuel economy than the 2H mode.
In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front and
rear wheels to rotate at the same speed. The 4H and 4L
positions are intended for loose, slippery road surfaces
only and not intended for normal driving. Driving in the 4H
and 4L positions on hard-surfaced roads will cause
increased tire wear and damage to the driveline
components. For further information on shifting into 4H or
4L
Úpage 143.
The instrument cluster alerts the driver that the vehicle is
in four-wheel drive, and the front and rear driveshafts are
locked together. The light will illuminate when the transfer
case is shifted into the 4H position.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type, and circumference on each wheel.
Any difference will adversely affect shifting and cause
damage to the transfer case.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
Shifting Procedures
2H TO 4H AUTO OR 4H AUTO TO 2H
Shifting between 2H and 4H AUTO can be made with the
vehicle stopped or in motion. The preferred shifting speed would be 0 to 45 mph (72 km/h). With the vehicle in
motion, the transfer case will engage/disengage faster if
you momentarily release the accelerator pedal after
completing the shift. Do not accelerate while shifting the
transfer case. Apply a constant force when shifting the
transfer case lever.
2H/4H AUTO TO 4H PART TIME OR 4H PART
TIME TO 2H/4H AUTO
Shifting between 2H/4H AUTO to 4H PART TIME can be
made with the vehicle stopped or in motion. The preferred
shifting speed would be 0 to 45 mph (72 km/h). With the
vehicle in motion, the transfer case will engage/disengage
faster if you momentarily release the accelerator pedal
after completing the shift. Do not accelerate while shifting
the transfer case. Apply a constant force when shifting the
transfer case lever.
NOTE:
 Do not attempt to make a shift while only the front or
rear wheels are spinning. The front and rear driveshaft
speeds must be equal for the shift to take place.
Shifting while only the front or rear wheels are spinning
can cause damage to the transfer case.
 Delayed shifts out of four-wheel drive may be experi -
enced due to uneven tire wear, low or uneven tire pres -
sures, excessive vehicle loading, or cold temperatures.
 Shifting effort will increase with speed, this is normal.
During cold weather, you may experience increased effort
in shifting until the transfer case fluid warms up. This is
normal.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the (N)
Neutral position without first fully engaging the parking
brake. The transfer case (N) Neutral position
disengages both the front and rear driveshafts from the
powertrain, and will allow the vehicle to roll, even if the
automatic transmission is in PARK (or manual
transmission is in gear). The parking brake should
always be applied when the driver is not in the vehicle.
4

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